ROBUST Series
High-Speed Precision Angular Contact
Ball Bearings for Machine Tool Spindles
■ Temperature tolerance and low heat generation
■ Smooth running even during sudden rapid acceleration
■ Higher speed and longer life
High-Speed Precision Angular Contact Ball Bearings
Bearing features indispensable to motorized main spindles—
temperature tolerance, seizure resistance and low heat
generation—have been improved to enable higher speeds
with minimal thermal deformation.
A major trend in the machine tool industry is for higher maximum spindle speeds. In addition, machines are
being required to perform a wider variety of tasks and undergo frequent tool changes. Under such conditions,
excellent high-speed performance is imperative and spindles must accelerate and decelerate faster. During
periods of rapid acceleration or deceleration, spindle bearings are subjected to severe thermal load conditions.
These conditions are caused by drastic changes in the ambient environment that result from heat generated
by the motor, housing cooling and other factors. Performing well under such conditions and being capable of
higher speeds than conventional precision bearings, the ROBUST Series bearings provide solutions for highspeed spindles of the 21st century.
1. Features
S type (balls and rings: bearing steel) H type (balls: silicon nitride, Si3N4/rings: bearing steel)
These bearings are designed for motorized and non-motorized spindles and feature the
optimal internal structure for minimizing heat generation and improving seizure resistance.
The H type can be lubricated with grease at speeds where conventional bearings require
oil/air lubrication (Fig. 1). Additionally, both the S type and H type are capable of speeds 20%
higher than conventional precision angular contact ball bearings.
H type angular contact ball bearings
X type (balls: silicon nitride, Si3N4/rings: SHX steel)
While this hybrid ceramic bearing has the same design as the S and H types, its rings are
made of SHX steel, a new steel developed by NSK. SHX has excellent seizure and wear
resistance during critical lubrication shortages. Also, its heat resistance is nearly equal to
M50 steel, which is widely used in bearings for jet aircraft engines. With the X type, grease
lubrication is feasible at even higher speeds than the H type (Fig. 1). In terms of both
surface and subsurface fatigue, SHX steel provides longer life (Figs. 3 ~ 6).
1
ROBUST Series
EX type (balls: silicon nitride, Si3N4/rings: SHX steel/Spinshot™ Technology)
EX bearings have the same specifications as the X type, but employ NSK’s exclusive
Spinshot™ lubrication system (Fig. 7). While previously only oil jet lubrication has been
feasible at speeds exceeding 2,000,000 dmn, the Spinshot™ lubrication system utilizes
a mixture of oil and air to enable the EX type to sustain such speeds (Fig. 1). The use
of oil/air instead of oil jets reduces overall costs by allowing the structure of the
spindle to be simplified and cutting down on the consumption of oil, an added
environmental benefit.
Please note that the EX type is not dimensionally interchangeable with conventional
precision angular contact ball bearings.
Notes: 1. Special heat-resistant, high-strength polyimide resin cages are used in the X and EX types for extremely high speeds. In the S and H types
and the X and EX types at low to moderate speeds, phenolic or polyamide cages are used.
2. For X and EX type bearings with outside diameters exceeding φ150, please consult NSK.
Grease
Steel balls
Oil/air
Conventional
Bearings
Grease
Ceramic balls
Oil/air
Grease
S type
Oil/air
Grease
H type
Oil/air
ROBUST Series
Grease
X type
Oil/air
Position preload Constant-pressure preload
EX type
d mn
Oil/air
1.0
2.0
3.0
4 . 0 x 10 6
Note: Limiting speeds vary depending not only on the bearing and lubrication method used, but also on the main
spindle driving system, cooling method, structure and other factors. Consider the above as a general
reference guide and consult NSK for limiting speeds of specific applications.
Fig. 1 Comparison of application ranges of conventional and ROBUST Series bearings under position preload
2
High-Speed Precision Angular Contact Ball Bearings
Optimal Internal Design
■ Improved temperature tolerance
Today, machining involves various cutting conditions within a wide range of speeds. Consequently, spindle temperatures vary
widely and cause changes in internal bearing load. The unique design of the ROBUST Series bearings minimizes the adverse
effect temperature variation has on internal bearing load.
■ Minimal heat generation
To ensure the accuracy of spindles by minimizing thermal displacement, suppression of bearing dynamic frictional loss is vital.
The ROBUST Series design controls dynamic frictional loss, reducing heat generation by approximately 20% when compared to
conventional bearings operating at the same speed.
Heat generation- Calculated values
(bore diameter: 65 mm; grease lubrication)
Heat generation, W
140
Conventional bearings
120
ROBUST Series
100
80
60
40
Temperature rise of outer ring- Measured values
(bore diameter: 65 mm; grease lubrication)
20
0
5
10
15
Speed, rpm (×103)
50
20
Temperature rise of
outer ring, °C
0
Conventional bearings
40
ROBUST Series
30
20
10
0
0
5
10
15
3
Speed, rpm (×10 )
Heat
PV value* generation
Conventional bearings
ROBUST Series
Temperature difference between inner and outer rings
With a lower PV value* and less heat generation,
ROBUST Series bearings operate with greater
stability than conventional precision bearings.
* PV value measures the relationship between ball and
raceway surface pressure and ball sliding speed.
Fig. 2 Analysis results on bearing dynamics
3
20
ROBUST Series
SHX Steel Used for Inner and Outer Rings of X and EX Types
SHX steel has heat resistance nearly equivalent to that of M50 steel and is superior to M50 in wear resistance, seizure
resistance and durability. As such, SHX is highly suited for use in machine tool spindles, which must run at high speeds
with a minimum supply of lubricant.
Heat resistance
900
Hardness, HV
850
800
750
700
650
SHX
SUJ2
M50
600
550
500
100
200
300
Tempering temperature,°C
400
Fig. 3.1 Tempering temperature and hardness
900
Hardness, Hv
800
700
600
SHX
SUJ2
M50
500
400
300
0
100
200
300
400
500
Temperature, °C
Fig. 3.2 High-temperature hardness
Wear resistance
Amount of wear, g
0.07
Load
SHX
SUJ2
M50
0.06
0.05
Lubricant
0.04
0.03
7 rpm
0.02
0.01
0
10 rpm
0
500
1000
1500
Sliding distance, m
2000
Test conditions
Surface pressure: 880 MPa
Sliding ratio: 30%
Lubrication: Spindle oil (2 cm3/min)
Temperature: Room temperature
Fig. 4 Wear resistance (2-cylinder wear test)
4
High-Speed Precision Angular Contact Ball Bearings
Seizure resistance
Test conditions
Lubrication: Oil bath
Speed: 6,000 rpm (constant)
PV value, (kgf/mm2• m/s)
Time until seizure, sec
Test conditions
Lubrication: None
Sliding condition: PV = 3,720N • mm2• m/s
(380 kgf • mm2• m/s)
600
500
400
300
200
100
(1)
0
-100
Load
1600
Rotating
1200
800
Fixed
400
(2)
SHX
M50
SUJ2
M50
Material
4-ball test
SHX
Material
Notes: (1) Oil shut-off point
(2) M50 seized before the oil shut-off point was reached.
Fig. 5.1 Dry seizure test (4-ball test)
Fig. 5.2 Seizure limit test (4-ball test)
These tests confirm that SHX is superior to M50 in seizure resistance. Silicon nitride balls offer even higher
seizure resistance.
Long life
Cumulative failure probability, %
Clean lubrication
99.9
99
SHX
SUJ2
90
50
Test conditions
Bearing: 6206
P/C: 0.71
Temperature: 160°C
Speed: 4,900 rpm
Oil film parameter, Λ: 5
10
5
1
10
2
3
10
4
10
10
Life, h
Fig. 6.1 Life test for subsurface-originated flaking
Cumulative failure probability, %
Contaminated lubrication
99.9
99
SHX
90
SUJ2
M50
50
Test conditions
Bearing: 6206
P/C: 0.28
Temperature: 140°C
Speed: 4,900 rpm
Foreign debris:
Hardness: Hv540
Size: 74 ~ 147 µm
10
5
1
1
2
10
10
Life, h
Fig. 6.2 Life test for surface-originated flaking
5
3
10
ROBUST Series
Spinshot™ Lubrication System
The EX type features the widely accepted Spinshot™ lubrication system for machine tool main spindles. This system ensures a
steady supply of lubricating oil to the bearing and excellent high-speed performance.
The Spinshot™ lubrication system is illustrated in Fig. 7. Oil/air (a mixture of the minimum necessary amount of oil and
compressed air) is fed from the lubrication device to the bearing via nozzles and oil scoops in the spacer. The nozzles in the
spacer are inclined outward so that centrifugal force makes the oil flow into the bearing with greater velocity as speed increases.
With the Spinshot™ lubrication system, the steady supply of lubrication and the cooling effect of the oil/air mixture greatly
increase the limiting speed of the bearing.
Please note that the EX type is not dimensionally interchangeable with conventional precision angular contact ball bearings.
Oil/air
Oil/air
Oil/air
Oil scoop
Spinshot™ spacer
Spinshot™ spacer
Fig. 7 Spinshot™ lubrication system
A
View of outer ring spacer from A
Fig. 8 Example of bearing arrangement (position preload)
6
High-Speed Precision Angular Contact Ball Bearings
2. Bearing Materials and Construction
Material
Type
Bearing construction
Inner ring
Outer ring
Balls
S
SUJ2
SUJ2
SUJ2
H
SUJ2
SUJ2
Si3N4
X
SHX
SHX
Si3N4
EX
SHX
SHX
Si3N4
Note: SUJ2 is equivalent to ASTM 52100.
3. Test Results
Outer ring temperature rise, °C
H type
50
Thermocouple
Bearing: 65BNR10TDBB
Preload when assembled: 196N (20 kgf)
Lubrication: Grease
40
30
H type
Conventional hybrid bearing
20
10
0
0
5
10
15
20
25
Speed, rpm (×103)
0.5
1
dmn
1.5
2
(×106)
Testing machine structure
Without cooled
housing
Bearing: 90BNR10TDB
Preload when assembled: 382N (40 kgf)
Lubrication: VG22, 0.03 cm3/16 min
40
30
H type
Conventional hybrid bearing
20
10
0
5
0
0.5
10
15
Speed, rpm (×103)
1
dmn
1.5
20
2
(×106)
Fig. 10 Comparison of temperature rise with oil/air lubrication
7
Thermocouple
With cooled
housing
Outer ring temperature rise, °C
Fig. 9 Comparison of temperature rise with grease lubrication
Testing machine structure
ROBUST Series
Outer ring temperature rise, °C
X type
60
Thermocouple
Bearing: 65BNRX10TDBB
Preload when assembled: 196N (20 kgf)
Lubrication: Grease
50
40
X type
Conventional hybrid bearing
30
20
10
0
0
5
10
15
Speed, rpm (×103)
0.5
1
dmn
20
25
1.5
2
(×106)
Testing machine structure
Outer ring temperature rise, °C
Fig. 11 Comparison of temperature rise with grease lubrication
40
Bearing: 65BNRX10TDBB
Preload when assembled: 49N (5 kgf)
Lubrication: VG32, 0.03 cm3/8 min
35
30
25
X type
Conventional
hybrid bearing
20
15
10
5
0
0
5
10
15
Speed, rpm (×103)
0.5
1
dmn
20
25
1.5
Testing machine structure
2
(×106)
Fig. 12 Comparison of temperature rise with oil/air lubrication
Outer ring temperature rise, °C
EX type
45
40
35
30
25
20
15
10
5
0
Thermocouple
Bearing: 65BNRE110T62DB
Preload when assembled: 98N (10 kgf)
Lubrication: Under race oil/air lubrication (Spinshot)
VG22, 0.03 cm3/4 min (2 nozzles)
EX type
0
5
10
0.5
15
20
Speed, rpm (×103)
1
25
1.5
2
dmn
30
2.5
(×106)
Testing machine structure
Temperature rise of cylinder, °C
Fig. 13 Temperature rise with oil/air lubrication and position preload
60
Bearing: 65BNRE110T62DT
55BNRE95T62DT
Preload (constant-pressure): 755N (77 kgf)
Lubrication: Under race oil/air lubrication (Spinshot)
50
40
Lubrication is provided one shot at
a time by one of 3 nozzles
30
Rear bearings
Front bearings
20
10
0
0
10
0.5
20
Speed, rpm (×103)
1
1.5
2
dmn
30
2.5
40
3
3.5
(×106)
Testing machine structure
Fig. 14 Temperature rise with oil/air lubrication and constant-pressure preload
8
High-Speed Precision Angular Contact Ball Bearings
4. Bearing Nomenclature
S type (balls and rings: bearing steel)
Example:
65 BNRS 10 TY DB L P4
Accuracy symbol
P4: ISO Class 4
P4A: NSK tolerance for BARS and BTRS
P3: Dimensions- ISO Class 4
Running accuracy- ISO Class 2
P2: ISO Class 2
Nominal bearing bore
Indicates type of bearing
BNRS: 18°
BARS: 30°
BTRS: 40°
Size series no.
10: Bore, outside diameter and width are same as 70 series
19: Bore, outside diameter and width are same as 79 series
10X: Bore and outside diameter are same as 70 series
(width is a special dimension)
Preload symbol
EL: Extra light
L: Light
CP: Preload (negative clearance)
(CP10: -10 µm)
CA: Axial clearance (CA10: +10 µm)
Cage symbol
T: Phenolic cage
TY: Polyamide cage
Arrangement symbol
DB: Back-to-back arrangement
DT: Tandem
DBB: 4-row arrangement
H type (balls: silicon nitride, Si3N4/rings: bearing steel)
Example:
65 BNR 10 TY DB L P4
See above
Nominal bearing bore
Size series no.
10: Bore, outside diameter and width are same as 70 series
19: Bore, outside diameter and width are same as 79 series
Indicates type of bearing-BNR: 18°
X type (balls: silicon nitride, Si3N4/rings: SHX steel)
Example:
65 BNRX 10 T DB L P4
See above
Nominal bearing bore
Size series no.
10: Bore, outside diameter and width are same as 70 series
19: Bore, outside diameter and width are same as 79 series
Indicates type of bearing-BNRX: 18°
EX type (balls: silicon nitride, Si3N4/rings: SHX steel/Spinshot™ Technology)
Example:
65 BNRE 110 T62 DB L P4
Nominal bearing bore
Indicates type of bearing
Nominal bearing outside diameter
9
See above
Cage symbol
T: Phenolic cage
T62: Polyimide cage
ROBUST Series
5. Tolerances for Boundary Dimensions and Running Accuracy
For most tolerances, i.e., P2, P3 and P4, refer to NSK catalog number E124, “Precision Rolling Bearings for MachineTool Spindles.” However, for the tolerances of BARS10X and BTRS10X series, which have Class 4A tolerance, refer to
Tables 1.1 and 1.2. Class 4A tolerance is an NSK specification. In Class 4A, all of the tolerances are the same as ISO
Class 4 except for those related to the outside diameter.
Table 1.1 Inner ring tolerances of BARS10X and BTRS10X series
d
Single plane
mean bore
dia. deviation
Deviation
of a single
bore dia.
(mm)
∆dmp
∆ds
Brg bore
over
incl
high
–
50
0
50
80
80
120
low
Bore dia. variation
in a single
radial plane
Mean bore
dia. variation
Vdmp
Vdp
Diameter series
9
0
high
low
max
max
-6
0
-6
6
5
0
-7
0
-7
7
120
0
-8
0
-8
150
0
-10
0
-10
Units: µm
Assembled brg
Radial runout
Inner ring
of assembled
brg inner ring
reference face
runout with bore
Kia
Sd
inner ring
face runout
with raceway
Inner ring
width variation
VBs
Sia
max
Single plane
mean outside
Deviation
of a single
D
dia. deviation
outside dia.
(mm)
∆Dmp
∆Ds
∆Bs (∆Cs)
max
max
max
max
high
low
3
4
4
4
3
0
-300
5
3.5
4
5
5
4
0
-500
8
6
4
5
5
5
4
0
-500
10
8
5
6
6
7
5
0
-750
Table 1.2 Outer ring tolerances of BARS10X and BTRS10X series
Brg outside
diameter
Deviation of a
single inner
ring width
Outside dia. variation
in a single
radial plane
VDp
Diameter series
Mean outside
dia. variation
VDmp
Units: µm
Radial runout
of assembled
brg outer ring
Kea
Variation of brg
outside surface
Assembled brg
outer ring
generatrix inclination
face runout
Outer ring
width variation
with outer ring face
with raceway
VCs
SD
Sea
9
0
over
incl
high
low
high
low
max
max
max
max
max
max
max
–
80
-30
-37
-30
-37
7
5
3.5
5
4
5
3
80
120
-40
-48
-40
-48
8
6
4
6
5
6
4
120
150
-50
-59
-50
-59
9
7
5
7
5
7
5
150
180
-50
-60
-50
-60
10
8
5
8
5
8
5
180
250
-50
-61
-50
-61
11
8
6
10
7
10
7
10
High-Speed Precision Angular Contact Ball Bearings
6. Preloads for Duplex Bearings
When determining the appropriate preload for your application, please consult NSK.
Table 2.1 BNRS19, BNR19 and BNRX19 Series
Axial Preload (N)
Bearing bore
diameter
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
120
130
BNRS19 (α = 18°)
EL
49
49
49
49
49
49
49
49
49
49
49
98
98
98
98
98
98
–
BNR19, BNRX19 (α = 18°)
L
147
147
157
167
167
176
186
186
186
196
196
294
294
343
343
392
412
–
EL
49
49
49
49
49
49
49
49
49
49
49
98
98
98
98
98
98
–
L
157
157
176
176
186
196
206
206
206
215
215
314
314
372
412
461
471
–
Table 2.2 BNRS10, BNR10 and BNRX10 Series
Axial Preload (N)
Bearing bore
diameter
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
120
130
11
BNRS10 (α = 18°)
EL
49
49
49
49
49
49
49
49
49
98
98
98
98
98
98
98
98
–
BNR10, BNRX10 (α = 18°)
L
108
118
118
118
118
127
137
235
245
343
343
343
343
343
441
539
588
–
EL
49
49
49
49
49
49
49
49
49
98
98
98
98
98
98
98
98
–
L
118
127
127
127
137
137
147
265
274
372
372
372
392
392
490
637
637
–
ROBUST Series
Table 2.3 BARS10X and BTRS10X Series
Axial Preload (N)
Bearing bore
diameter
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
120
130
BARS10X (α = 30°)
EL
–
196
196
245
245
245
245
245
245
343
343
392
392
392
392
392
392
392
L
–
441
441
490
637
637
686
931
931
1 130
1 130
1 670
1 760
1 810
1 860
1 910
2 060
2 600
BTRS10X (α = 40°)
EL
–
294
294
343
343
392
392
392
392
539
539
539
539
588
588
588
588
588
L
–
686
735
784
784
882
931
1 570
1 670
1 860
1 910
2 890
2 990
3 090
3 190
3 280
3 530
4 510
Note: α is the contact angle
12
High-Speed Precision Angular Contact Ball Bearings
BNRS19
BNR19
BNRX19
B
r
r1
r
ra
ra
r
Material
13
Inner rings
Outer rings
Balls
BNRS19
SUJ2
SUJ2
SUJ2
BNR19
SUJ2
SUJ2
Si3N4
BNRX19
SHX
SHX
Si3N4
d
Boundary Dimensions
(mm)
D
B
35
55
40
φ da
φ Da
φd
φD
Contact angle 18°
a
Basic Load Ratings
(N)
r
min
r1
min
10
0.6
0.3
62
12
0.6
45
68
12
50
72
55
Cr
{kgf}
Cor
Cr
Cor
8 300
4 600
845
470
0.3
10 300
5 900
1 050
600
0.6
0.3
11 000
6 700
1 120
685
12
0.6
0.3
11 700
7 500
1 190
765
80
13
1
0.6
13 300
8 900
1 350
905
60
85
13
1
0.6
13 500
9 400
1 380
955
65
90
13
1
0.6
14 100
10 300
1 440
1 050
70
100
16
1
0.6
19 500
13 900
1 990
1 420
75
105
16
1
0.6
19 900
14 600
2 030
1 490
80
110
16
1
0.6
20 300
15 400
2 060
1 570
85
120
18
1.1
0.6
27 000
20 300
2 750
2 070
90
125
18
1.1
0.6
29 000
23 000
2 950
2 350
95
125
18
1.1
0.6
29 500
24 000
3 000
2 450
100
140
20
1.1
0.6
35 000
27 100
3 550
2 760
ROBUST Series
rb
Dynamic Equivalent Load
φ da
φ Db
ra
P = XFr + YFa
Single, DT
Nominal
Contact
Angle
Cor*
18°
—
e
iFa
0.57
Fa/Fr ≤e
Fa/Fr >e
Fa/Fr ≤e
Fa/Fr >e
X
Y
X
Y
X
X
1
0
0.43
1
1
Nominal
Contact
Angle
18°
35BNRS19
35BNR19
35BNRX19
40BNRS19
40BNR19
40BNRX19
45BNRS19
45BNR19
45BNRX19
50BNRS19
50BNR19
50BNRX19
55BNRS19
55BNR19
55BNRX19
60BNRS19
60BNR19
60BNRX19
65BNRS19
65BNR19
65BNRX19
70BNRS19
70BNR19
70BNRX19
75BNRS19
75BNR19
75BNRX19
80BNRS19
80BNR19
80BNRX19
85BNRS19
85BNR19
85BNRX19
90BNRS19
90BNR19
90BNRX19
95BNRS19
95BNR19
95BNRX19
100BNRS19
100BNR19
100BNRX19
Y
Y
1.09 0.70 1.63
*For i, use 2 for DB and DF and 1 for DT.
Static Equivalent Load
Bearing Numbers
DB or DT
Abutment and Fillet Dimensions
(mm)
Da
Db
ra
max
max
max
Single, DT
P 0 = X0 F r + Y 0 F a
DB or DF
X0
Y0
X0
Y0
0.5
0.42
1
0.84
Single or DT mounting
when
Fr >0.5F + Y0 Fa
use P0 = Fr
rb
max
Mass
(kg)
approx
0.6
0.3
0.074
3
59.5
0.6
0.3
0.109
4.8
63
65.5
0.6
0.3
0.129
5.2
55
67
69.5
0.6
0.3
0.130
5.9
17.5
61
74
75
1
0.5
0.182
7.4
18.3
66
79
80
1
0.5
0.195
7.2
19.1
71
84
85
1
0.5
0.208
8.6
21.8
76
94
95
1
0.5
0.338
14
22.6
81
99
100
1
0.5
0.358
15
23.4
86
104
105
1
0.5
0.377
16
25.7
92
113
115
1
0.6
0.534
24
26.5
97
118
120
1
0.6
0.568
24
27.3
102
123
125
1
0.6
0.597
23
29.5
107
133
135
1
0.6
0.800
31
Eff. Load Center
(mm)
a
da
min
12.3
40
50
52.5
14.3
45
57
15.2
50
15.9
Internal Free
Space
(cm3/row)
14
High-Speed Precision Angular Contact Ball Bearings
BNRS10
BNR10
BNRX10
B
r
r1
r
r
ra
ra
da
Da
d
D
Contact angle 18°
Material
15
Inner rings
Outer rings
Balls
BNRS10
SUJ2
SUJ2
SUJ2
BNR10
SUJ2
SUJ2
Si3N4
BNRX10
SHX
SHX
Si3N4
Boundary Dimensions
(mm)
B
r
min
d
D
35
62
14
40
68
45
a
Basic Load Ratings
(N)
{kgf}
r1
min
Cr
Cor
Cr
Cor
1
0.6
9 150
5 500
935
560
15
1
0.6
9 650
6 150
985
630
75
16
1
0.6
10 700
6 950
1 090
710
50
80
16
1
0.6
11 200
7 700
1 140
785
55
90
18
1.1
0.6
13 900
9 800
1 420
995
60
95
18
1.1
0.6
14 500
10 700
1 480
1 090
65
100
18
1.1
0.6
15 100
11 600
1 540
1 180
70
110
20
1.1
0.6
20 500
15 200
2 090
1 550
75
115
20
1.1
0.6
20 800
16 000
2 120
1 630
80
125
22
1.1
0.6
24 500
19 000
2 500
1 940
85
130
22
1.1
0.6
24 800
19 900
2 530
2 030
90
140
24
1.5
1
32 500
25 800
3 300
2 630
95
145
24
1.5
1
33 000
26 900
3 350
2 740
100
150
24
1.5
1
33 500
28 000
3 400
2 860
ROBUST Series
rb
Dynamic Equivalent Load
da
Db
ra
P = XFr + YFa
Single, DT
Nominal
Contact
Angle
Cor*
18°
—
e
iFa
0.57
Fa/Fr ≤e
Fa/Fr >e
Fa/Fr ≤e
Fa/Fr >e
X
Y
X
Y
X
X
1
0
0.43
1
1
Nominal
Contact
Angle
18°
35BNRS10
35BNR10
35BNRX10
40BNRS10
40BNR10
40BNRX10
45BNRS10
45BNR10
45BNRX10
50BNRS10
50BNR10
50BNRX10
55BNRS10
55BNR10
55BNRX10
60BNRS10
60BNR10
60BNRX10
65BNRS10
65BNR10
65BNRX10
70BNRS10
70BNR10
70BNRX10
75BNRS10
75BNR10
75BNRX10
80BNRS10
80BNR10
80BNRX10
85BNRS10
85BNR10
85BNRX10
90BNRS10
90BNR10
90BNRX10
95BNRS10
95BNR10
95BNRX10
100BNRS10
100BNR10
100BNRX10
Y
Y
1.09 0.70 1.63
*For i, use 2 for DB and DF and 1 for DT.
Static Equivalent Load
Bearing Numbers
DB or DT
Abutment and Fillet Dimensions
(mm)
Da
Db
ra
max
max
max
Single, DT
P 0 = X0 F r + Y0 Fa
DB or DF
X0
Y0
X0
Y0
0.5
0.42
1
0.84
Single or DT mounting
when
Fr >0.5F + Y0 Fa
use P0 = Fr
rb
max
Mass
(kg)
approx
Internal Free
Space
(cm3/row)
1
0.5
0.162
5.3
63
1
0.5
0.204
7
69
70
1
0.5
0.259
8.9
56
74
75
1
0.5
0.281
9.9
20.8
62
83
85
1
0.6
0.418
13
21.6
67
88
90
1
0.6
0.453
13
22.4
72
93
95
1
0.6
0.476
15
24.6
77
103
105
1
0.6
0.649
22
25.4
82
108
110
1
0.6
0.684
24
27.7
87
118
120
1
0.6
0.928
29
28.5
92
123
125
1
0.6
0.972
31
30.7
99
131
134
1.5
0.8
1.25
41
31.5
104
136
139
1.5
0.8
1.3
43
32.3
109
141
144
1.5
0.8
1.35
45
Eff. Load Center
(mm)
a
da
min
14.9
41
56
57
16.3
46
62
17.7
51
18.6
16
High-Speed Precision Angular Contact Ball Bearings
BARS10X
Contact angle 30°
BTRS10X
Contact angle 40°
Material
Inner rings
Outer rings
Balls
BARS10X
SUJ2
SUJ2
SUJ2
BTRS10X
SUJ2
SUJ2
SUJ2
Note: These bearings are only available in Class 4A tolerance (Tables 1.1 and 1.2, page 10).
17
d
Boundary Dimensions
(mm)
D
2B
40
68
45
Basic Load Ratings
(N)
{kgf}
r
min
r1
min
Ca
Coa
Ca
Coa
27
1
0.6
11 700
14 100
17 200
19 600
1 200
1 440
1 760
2 000
75
28.5
1
0.6
13 000
15 600
19 500
22 200
1 330
1 590
1 980
2 260
50
80
28.5
1
0.6
13 600
16 300
21 400
24 400
1 390
1 660
2 190
2 490
55
90
33
1.1
0.6
16 900
20 200
27 300
31 000
1 720
2 060
2 790
3 150
60
95
33
1.1
0.6
17 600
21 100
29 800
34 000
1 800
2 150
3 050
3 450
65
100
33
1.1
0.6
18 300
21 900
32 500
37 000
1 870
2 230
3 300
3 750
70
110
36
1.1
0.6
24 800
29 700
42 500
48 500
2 530
3 050
4 350
4 950
75
115
36
1.1
0.6
25 300
30 000
44 500
50 500
2 570
3 100
4 550
5 150
80
125
40.5
1.1
0.6
29 700
35 500
53 000
60 500
3 050
3 600
5 400
6 150
85
130
40.5
1.1
0.6
30 000
36 000
55 500
63 000
3 050
3 650
5 650
6 450
90
140
45
1.5
1
39 500
47 000
72 000
82 000
4 000
4 800
7 350
8 350
95
145
45
1.5
1
40 000
48 000
75 000
85 500
4 100
4 900
7 650
8 700
100
150
45
1.5
1
40 500
48 500
78 500
89 000
4 150
4 950
8 000
9 050
105
160
49.5
2
1
46 000
55 000
89 500
102 000
4 700
5 600
9 100
10 400
110
170
54
2
1
52 000
62 000
102 000
116 000
5 300
6 350
10 400
11 800
120
180
54
2
1
53 500
64 000
110 000
125 000
5 450
6 550
11 200
12 700
130
200
63
2
1
67 500
80 500
133 000
151 000
6 850
8 200
13 500
15 400
ROBUST Series
2B
r1
r1
r
40BARS10X
40BTRS10X
45BARS10X
φd
φ Db
φ da
r
φD
Bearing Numbers
rb
da
min
Abutment and Fillet Dimensions
(mm)
Db
max
rb
max
Mass
(kg)
approx
Internal Free
Space
(cm3/row)
50
63
0.5
0.200
6.1
56
70
0.5
0.255
7.4
45BTRS10X
50BARS10X
50BTRS10X
61
75
0.5
0.272
8
55BARS10X
55BTRS10X
68
84
0.6
0.412
13
60BARS10X
60BTRS10X
73
89
0.6
0.433
12
65BARS10X
65BTRS10X
78
94
0.6
0.472
14
70BARS10X
70BTRS10X
85
104
0.6
0.637
20
75BARS10X
75BTRS10X
90
110
0.6
0.671
21
80BARS10X
80BTRS10X
97
117
0.6
0.912
28
85BARS10X
85BTRS10X
102
122
0.6
0.971
29
90BARS10X
90BTRS10X
109
132
0.8
1.27
40
95BARS10X
95BTRS10X
113.5
137
0.8
1.32
42
100BARS10X
100BTRS10X
119
142
0.8
1.37
43
105BARS10X
105BTRS10X
125
151
1
1.74
56
110BARS10X
110BTRS10X
132
159
1
2.23
67
120BARS10X
120BTRS10X
142
169
1
2.39
72
130BARS10X
130BTRS10X
156
188
1
3.57
110
18
NSK Ltd. has a basic policy not to export any products or technology that have
been designated as controlled items by export related laws.
When exporting such products that are shown in this pamphlet, the laws of the
exporting country must be observed.
For more details, please contact any of the following NSK offices.
Worldwide Manufacturing and Marketing Organization
NSK LTD.-Headquarters
http://www.nsk.com
Japan:
Tokyo
AMERICAS & EUROPE DEPARTMENT Phone: 03-3779-7120
ASIA MARKETING & SALES DEPARTMENT Phone: 03-3779-7121
NSK AMERICAS, INC.
[AMERICAN HEADQUARTERS]
U.S.A.:
Ann Arbor
Phone: 734-761-9500
NSK CORPORATION
U.S.A.:
Ann Arbor
Phone: 734-761-9500
[Precision Products Business Unit]
U.S.A.:
Chicago
Phone: 630-924-8000
[TECHNICAL CENTER]
U.S.A.:
Ann Arbor
Phone: 734-668-0877
[BRANCHES and DISTRIBUTION CENTERS]
U.S.A.:
Los Angeles
Phone: 562-926-2975
NASTECH
U.S.A.:
Vermont
Phone: 802-442-5448
NSK SAFETY TECHNOLOGY, INC.
U.S.A.:
Detroit
Phone: 248-338-4959
NSK-RHP AMERICAN DISTRIBUTION CENTER, INC.
U.S.A.:
Miami
Phone: (305) 261-7824
NSK-RHP CANADA INC.
Canada:
Toronto
Phone: 905-890-0740
NSK RODAMIENTOS MEXICANA, S.A. DE C.V.
Mexico:
Mexico City
Phone: 5-301-2741
NSK DO BRASIL INDUSTRIA E COMERCIO
DE ROLAMENTOS LTDA.
Brazil:
São Paulo
Phone: 011-269-4700
NSK-RHP EUROPE LTD. [European Headquarters]
England:
Ruddington
Phone: 0115-936-6464
NSK-RHP EUROPE LTD. WARSAW LIAISON OFFICE
Poland:
Warsaw
Phone: 022-645-1525, 1526
NSK BEARINGS EUROPE LTD.
England:
Peterlee
Phone: 0191-586-6111
NSK-RHP EUROPEAN TECHNOLOGY CO., LTD.
England:
Ruddington
Phone: 0115-940-5409
NSK-RHP UK LTD.
England:
Ruddington
Phone: 0115-936-6600
NSK-RHP DEUTSCHLAND GMBH.
Germany:
Düsseldorf
Phone: 02102-481-0
NSK-RHP FRANCE S.A.
France:
Paris
Phone: 01 30 57 39 39
NSK-RHP NEDERLAND B.V.
Netherlands: Amsterdam
Phone: 020-6470711
NSK-RHP EUROPEAN DISTRIBUTION CENTRE B.V.
Netherlands: Amsterdam
Phone: 020-6470711
NSK-RHP ITALIA S.P.A.
Italy:
Milano
Phone: 02-995191
NSK-RHP IBERICA, S.A.
Spain:
Barcelona
Phone: 93-575-1662
NSK ISKRA S.A.
Poland:
Kielce
Phone: 041-366-61-11
NSK-RHP BEARINGS MIDDLE EAST TRADING CO., LTD.
Turkey:
Istanbul
Phone: 216-463-6150
NSK-RHP SOUTH AFRICA (PTY) LTD.
South Africa: Johannesburg
Phone: 011 (458) 3600
NASTECH EUROPE LTD.
England:
Coventry
Phone: 01203-854500
NSK INTERNATIONAL (SINGAPORE) PTE LTD.
Singapore:
Singapore
Phone: 2730357
NSK SINGAPORE (PRIVATE) LTD.
Singapore:
Singapore
Phone: 2781711
NSK-RHP AUSTRALIA PTY. LTD.
Australia:
Melbourne
Phone: 03-9764-8302
NSK-RHP BEARINGS NEW ZEALAND LTD.
Phone: 09-276-4992
New Zealand: Auckland
NSK BEARINGS (THAILAND) CO., LTD.
Thailand:
Bangkok
Phone: 02-6412150~58
NSK SAFETY TECHNOLOGY (THAILAND) CO., LTD.
Phone: (038) 214-317-8
Thailand:
Chonburi
SIAM NASTECH CO., LTD.
Thailand:
Chachoengsao Phone: 038-522-343~350
PT. NSK BEARINGS MANUFACTURING INDONESIA
Indonesia:
Jakarta
Phone: 021-898-0155
NSK BEARINGS (MALAYSIA) SDN. BHD.
Malaysia:
Kuala Lumpur
Phone: 03-758-4396
NSK MICRO PRECISION (M) SDN. BHD.
Malaysia:
Kuala Lumpur
Phone: 03-961-6288
RANE NASTECH LTD.
India:
Madras
Phone: 4114-65313, 65314
Phone: 4114-65365, 66002
NSK KOREA CO., LTD.
Korea:
Seoul
Phone: 02-3287-0300
NSK-RHP HONG KONG LTD.
China:
Hong Kong
Phone: 2739-9933
KUNSHAN NSK HS CO., LTD.
China:
Kunshan
Phone: 0520-7305654
GUIZHOU HS NSK BEARINGS CO., LTD.
China:
Anshun
Phone: 0853-3521505
TAIWAN NSK PRECISION CO., LTD.
Taiwan:
Taipei
Phone: 02-2591-0656
NSK REPRESENTATIVE OFFICES
India:
Chennai
Phone: 044-4334732
China:
Beijing
Phone: 010-6590-8161~3
RHP BEARINGS LIMITED
England:
Newark
Phone: 01636-605123
Specifications are subject to change without notice and without any obligation on the part of the manufacturer. Every care has been taken to ensure accuracy of the data contained
in this catalog, but no liability can be accepted for any loss or damage suffered through errors or omission. We will gratefully acknowledge any additions or corrections.
CAT. No. E1221 1999 G-11 Printed in Japan ©NSK Ltd. 1999